1. Field of the Invention
The present invention relates to a variable-displacement compressor comprising a swash plate contained in a control pressure chamber so as to rotate integrally with a rotary shaft and to be inclined relative to the rotary shaft, plural pistons arranged about the rotary shaft and reciprocally moving depending upon the inclination of the swash plate, and swash plate inclination guide means for guiding the inclination of the swash plate, wherein the pressure in the control pressure chamber is controlled to control the inclination of the swash plate.
2. Description of the Related Art
In the variable-displacement compressors of this type disclosed in Japanese Unexamined Patent Publications (Kokai) No. 10-246181 and No. 11-201032, the angle of inclination of a swash plate decreases with an increase in the pressure in the crank chamber (control pressure chamber referred to in this specification) and the discharge capacity decreases. On the other hand, the angle of inclination of the swash plate increases with a decrease in the pressure in the crank chamber, and the discharge capacity increases. In the variable-displacement compressor which controls:.the capacity based on the adjusted pressure in the crank chamber, on the other hand, a maximum angle of inclination of the swash plate is determined by a rotary support member which rotates integrally with the rotary shaft and supports the swash plate via a hinge mechanism upon- receiving the inclination of the swash plate.
The swash plate is made of aluminum from the standpoint of reducing the weight. However, direct contact between the rotary support member made of iron and the swash plate made of aluminum causes wear at the contact portion of the swash plate. The contact portion of the swash plate that is worn out causes a change in the maximum angle of inclination of the swash plate. In the compressors disclosed in Japanese Unexamined Patent Publications (Kokai) No. 10-246181 and No. 11-201032, a weight made of iron is attached to the swash plate so that the weight made of iron comes in contact with the rotary support member. The constitution in which iron comes into contact with iron prevents wear, and a change in the maximum angle of inclination of the swash plate does not occur.
The weight is used for stably controlling the capacity. However, the weight distribution of the weight for stably controlling the capacity is affected by the shape of the weight. It is difficult to determine the shape of the weight for specifying a maximum angle of inclination of the swash plate in consideration for a suitable shape of the weight that greatly affects the operation for stably controlling the-capacity.
It is an object of the present invention to easily determine the maximum angle of inclination of a swash plate without causing a change in the maximum angle of inclination that results from a wear.
In order to accomplish the above-mentioned object, the present invention deals with a variable-displacement compressor comprising a swash plate contained in a control pressure chamber so as to rotate integrally with a rotary shaft and to be inclined relative to the rotary shaft, plural pistons arranged about the rotary shaft and reciprocally moving depending upon the inclination of the swash plate, and swash plate inclination guide means for guiding the inclination of the swash plate, the pressure in the control pressure chamber being controlled to control the inclination of the swash plate, wherein the swash plate inclination guide means includes a guide member having a passage-limiting cam, and to-be-guided members that are guided in slide contact with the passage-limiting cam, the guide member is formed integrally with the rotary shaft, the to-be-guided members are formed integrally with the swash plate, and a maximum inclination angle determining means is provided to set the swash plate at a position at where the angle of inclination of the swash plate becomes a maximum due to the contact of the guide member with the to-be-guided members.
The constitution for determining a maximum angle of inclination of the swash plate, based on the contact of the guide member constituting the swash plate inclination guide means with the to-be-guided members, is such that the guide member and the to-be-guided members are made of an iron-type material, and that the maximum angle of inclination is easily set while being free from being changed by the wear.
The present invention may be more fully understood from the description of the preferred embodiments of the invention set forth below together with the accompanying drawings.